I just got my 82 trans am running with the new TPI setup. It runs great except it is very hard to start when its cold and there is a strange high pitch noise coming from the rear of the intake. It sounds like when someone blows up a balloon and stretches the opening as the air escapes. It changes pitch as rpm changes and when i shut the engine off the sound fades away instead of stopping immediately. At first i thought it was the egr valve as I did not use a gasket when I installed it. I added a gasket, still makes the noise. Then I thought it was my fuel pressure regulator (this is the area where it sounds the loudest) so I installed my TPIS adjustable fuel pressure regulator and it still makes the noise. When I started it up after installing the fpr the sound was not present but as it sat and idled it came back again. My personal thoughts are maybe there is something stuck in the fuel rail, or maybe it is the cold start valve since i dont remember putting an o-ring in although it sounds slightly louder on the passenger side. Anyone had a similar noise?

 

I've noticed lately that I have a high pitch noise too, but I think mine is comming from my compressor for the A/C. I don't know what might be causing the noise except a possible vaccum leak. Good luck.